Human asexuality has been defined as a lack of sexual attraction to others, although its nature is not well understood. Asexual men's genital and subjective sexual arousal patterns were compared to sexual men's to better understand asexual men's sexual response patterns. Using a penile plethysmograph to measure genital arousal, 20 asexual, 27 heterosexual, and 22 gay cisgender men (M age = 28.28, SD = 9.41) viewed erotic films depicting sexual activity or masturbation, and a subsample engaged in sexual fantasy of their choosing. Questionnaires assessing sexual function and behavior were also completed. Asexual men scored lower on sexual desire and orgasmic function, higher on sexual aversion, and did not differ on overall sexual satisfaction. Compared with gay and heterosexual men, asexual men demonstrated lower genital and subjective sexual arousal to the erotic films but displayed similar sexual arousal when engaging in sexual fantasy. Asexual men's lower levels of sexual excitation rather than their higher levels of sexual inhibition were associated with lower responses to the erotic films. These findings suggest asexual men have preferred sexual stimuli that differ from sexual men and have a similar capacity for sexual arousal as sexual men. Collectively these findings add to a growing literature aiming to understand the nature of asexuality.